Perhaps you should try some spelling variations:
trinh chao » trinh chat, trinh han, trinh giao
thai viet » thi viet, tai viet, mai viet
trinh cao » trinh cau, tinh cao, trinh cho
trinh co » trinh cong, trinh hoa, trinh ky
loi viet » loai viet, oi viet, doi viet
chao lan » cao lan, chao van, chao yang
hoi viet » hai viet, oi viet, cuoi viet
trinh do » trinh ky
co thai » do thai, ca thai, co hai
cac cay » ca cay, cac cau, tac cay
cao van » cac van, dao van, cao dang
cac cam » cad cam, cac cau, cac ham
cac cap » cao cap, cac cau, cac tap
do lan » do van, do ban, do dan
cay co » cac co, tay co, cay cong
co lan » cao lan, co ban, co dan
cap co » cap cho, tap co, cap do
lan va » luan va, lanh va, lan van
van va » van vat, van van, ban va
cam co » cac co, nam co, lam co
co hoi » co hoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((( cong trinh co lan va cac cay co thai viet nam ) OR ( cong trinh do lan va cac cay co thai viet nam ))) or ((( cong trinh chao lan va cac cap co loi viet nam ) or ( cong trinh cao van va cac cam co hoi viet nam ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((( cong trinh co lan va cac cay co thai viet nam ) OR ( cong trinh do lan va cac cay co thai viet nam ))) OR ((( cong trinh chao lan va cac cap co loi viet nam ) OR ( cong trinh cao van va cac cam co hoi viet nam )))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((( cong trinh co lan va cac cay co thai viet nam ) OR ( cong trinh do lan va cac cay co thai viet nam ))) or ((( cong trinh chao lan va cac cap co loi viet nam ) or ( cong trinh cao van va cac cam co hoi viet nam ))))".
• Adding a wildcard symbol may retrieve word variants: (((( cong trinh co lan va cac cay co thai viet nam ) OR ( cong trinh do lan va cac cay co thai viet nam ))) or ((( cong trinh chao lan va cac cap co loi viet nam ) or ( cong trinh cao van va cac cam co hoi viet nam ))))*.